10x multiplier isn't an especially good naked run either, but 10x multiplier and a final score of 33k is awful. That's just either not hitting many notes (avoiding the vocal track and lingering on drum+bass on slower passages?) or not sustaining Blitz. My last 10x naked run I still clocked into the 44-45k range.
I'm not a great player (no golds yet), but I can get a One Week naked-run multiplier up to 12. Not 12s across the board (yet), but at least Vocals at 12 and everything else 9+.
There's really only two things you need to know about that song for naked runs: first, get Keyboards up early in the first leg because there are no keys late in the first leg and if you didn't give them attention early your first checkpoint will be lousy (and as an exponential-growth game, an early bad checkpoint is disaster); and second, when all else fails, Vocals.